This invention relates to a machine tool for complex machining operations using a complex tool, having installed thereon a plurality of inserts on a single holder portion, wherein the tool is capable of performing turning machining and rotational tool machining operations, such as drilling/milling machining operations, with one tool.
In a conventional machine tool, the available tools can be divided into tools for turning machining operations, versus tools for drilling/milling machining operations. For every change in the type of machining operation to be conducted, the tool installed on a tool rest may need to be exchanged. The previous tool is detached and the next tool is attached in its place, and used as necessary, for so long as that next tool is appropriate to accomplish the machining operation to be executed at that point in the sequence of operations, after which it in turn is replaced.
Thus with such a machine tool, it may be necessary to exchange tools every time that machining demands change. The time spent to exchange tools lowers machining efficiency. A recent proposal is to provide a complex tool wherein a plurality of inserts is installed on a single tool so as to save trouble during tool exchanges and thereby to improve machining efficiency.
But, it is absolutely impossible for an operator to sufficiently know the machining demands to be placed on such a complex tool in advance, at the time of composing the machining program. So, development of a machine tool capable of machining operations with a complex tool, without relying on an operator""s previous knowledge of the complex tool, is desired.
The object of the present invention is to provide a complex machining machine tool facilitating use with no preliminary knowledge concerning the complex tool, taking the above-mentioned circumstances into consideration.
The invention concerns a complex machining machine tool having a tool rest capable of attachably and detachably receiving a complex tool having a plurality of inserts thereon, capable of a plurality of kinds of machining operations on a workpiece with said complex tool, by selectively indexing and using said insert when installed on said complex tool. The complex machining machine tool comprises:
a spindle, rotatably supported, and defining a Z-axis as its center;
said tool rest being free to move and drive in an X-axis direction, perpendicular to said Z-axis, and being free to rotate, position and drive in a B-axis direction, with a Y-axis perpendicular to said X-axis and Z-axis as its center;
a tool file storing tool data concerning a tool to be used in a sequence of programmed machining operations;
said complex tool registered in said tool file as a plurality of virtual tools; a plurality of said virtual tools being virtually set for each said complex tool and corresponding to machining operations that are capable of being performed with said complex tool;
said virtual tools including a turning tool and a milling tool;
said tool data being stored for every said virtual tool;
said tool data storing an angle of said B-axis direction, concerning each virtual tool at which said tool can be positioned, when said virtual tool is used to define a B-axis angle; and
machining executing means operable for reading out the tool data of each corresponding virtual tool from said tool file, responsive to machining instructions identifying said virtual tool, which virtual tool is virtually defined and set for said complex tool, the machining instructions being stored in said machining program, and for executing machining operations with said virtual tool which is virtually set for the complex tool, and using the complex tool on the basis of said tool data.
According to the invention, a plurality of virtual tools is set in the tool file according to the machining capabilities of the complex tool. Then, the machining program can designate tool finishes by designating just the virtual tool to be used, and an operator can use the complex tool in a manner similar to the ways a usual tool is used, without the need to understand and be conscious of the complex tool.
The angle in the B-axis direction at which the tool is positioned when the virtual tool is used, is stored as the B-axis angle for each virtual tool. It is not necessary to set the B-axis angle when an operator commences use of the virtual tool, making it easy for the operator to use the complex tool.
According to another aspect of the complex machining machine tool, a tool length for the complex tool can be stored and applicable for each insert.
Preferably, the tool length is stored for each insert. Then, the tool length can be maintained regardless of the machining sequence, such as milling and turning with the insert. So, maintenance is easy.
An interference judging means can be provided for judging whether or not interference will occur between a workpiece to be machined and each said virtual tool. This can involve simulating the machining program to be executed. A B-axis angle changing means is provided for changing and setting the B-axis angle, so as to shift the B-axis angle applicable to the virtual tool, based on the B-axis angle stored in said tool data. The angle is modified by a predetermined amount and direction by which said complex tool is displaced from said workpiece in case where the interference judging means predicts a position conflict between said workpiece to be machined and said each virtual tool. According to another aspect, the B-axis angle changing means changes and sets the B-axis angle (the angle of {circle around (4)} in FIG. 10) for the virtual tool as stored in the tool data, so as to shift by a predetermined amount in the direction by which the complex tool is spaced from the workpiece, in a case where interference is predicted (for instance, the cases as shown in FIGS. 11(a) (c), (d)). If the workpiece and the tool are predicted to interfere with each other when using the complex tool, the B-axis angle is changed so as automatically to avoid the interference. Therefore, an operator can execute required machining operations without concern as to the B-axis angle of the complex tool 21.
A maximum shifting quantity can be set for the amount by which the B-axis angle can be permitted to be shifted by said B-axis angle changing means. The B-axis angle then is controlled so as not to shift more than said maximum shifting quantity.
In a case where the B-axis angle is not permitted to be shifted beyond a maximum shift quantity, and a situation occurs that would result in the B-axis angle being shifted by more than the predetermined quantity, such a function as the virtual tool can be avoided in programming or omitted, and proper machining can be continued.